An early day motion to defend the minimum wage was signed by 102 Labour MPs within four hours of it being tabled and another 23 MPs have now signed it.

On Wednesday, Gordon Brown even urged MPs to defeat the bill, saying: "We supported it in 1997, we continue to support it. We are determined to keep the minimum wage".

Mr Chope's bill aimed to scrap the minimum wage to allow people to "freely negotiate" their level of pay, a step which would boost employment in the recession, he maintained.

The Conservative MP said his bill called for "the restoration of the basic human right - the right to work" but unions argue that the absence of a fixed minimum wage would facilitate workers' exploitation.

Unison's general secretary Dave Prentis said to the Press Association: "I am delighted that Christopher Chope and his Tory cabal have failed in their attempt to turn the clock back to the days of poverty pay where workers are exploited by unscrupulous bosses.

"Unison fought long and hard to establish the statutory national minimum wage, in the teeth of opposition and unfounded scaremongering about massive job losses. We will continue to resist any attempt to dilute or abolish it."

The campaign to defeat the bill, backed by Usdaw and Unison was led by John Prescott, who launched the Wage Concern website and petition which received more than five thousands signature.